This is the second of "Akai" (Red) series the then big singing idol Momoe Yamaguchi has starred in.
Sachiko (Momoe Yamaguchi) the only daughter of Shigeru (Ken Utsui) and Toshie Ooshima (Kaoru Yachigusa, and Misako Watanabe) is really the daughter of Sagara (Hiroyuki Nagato) who had an affair with Shigeru's younger sister Rie (Keiko Kishi) 17 years ago. Sachiko while visiting her father at the University's med department gets involved in a boiler explosion accident that also spread radiation from Cobalt 60 that's used for cancer treatment, and gets a fatal dose of radiation. As a result, Sachiko contracts leukemia and has only few month to live. Sachiko, not knowing that Sagara's son Mitsuo (Tomokazu Miura) is actually her half brother, falls in love with him. To make matter worse, Sachiko has a rare blood type RH- AB, and has difficulty finding blood for transfusion. Mitsuo, and Sagara not surprisingly has this blood type also (since they're brother and father to her), but she doesn't know that they are related. Gradually Mitsuo and Sagara begins to understand that Sachiko is actually their family, but they choose not to disclose this to Sachiko. Sachiko decides to go for med school per Mitsuo's advise, but her health starts to deteriorate due to her Leukemia.
Although the plot seems rather complex, story runs seamlessly due to the superb screen play by various screen writers. Both Momoe Yamaguchi and Tomokazu Miura were relative new comers to acting, but they are supported by an all star cast of most experienced actors of the time. Ken Utsui puts in a superb acting and holds the integrity of the entire story together. About 60% of all acting is done by him (no kidding). All this makes this one of the best suspense home drama ever to come out of Japan or anywhere else.
High quality of this series makes it hold up to repeat viewing, and even after 35 years, this series is syndicated in Japan and other parts of Asia from time to time, which attests to its popularity.
This was the first time Tomokazu Miura and Momoe Yamaguchi appeared together in a TV drama. They eventually tie the knot and become husband and wife team. Superbly crafted TV series that's worth watching even today.